Add transformerconfig package and default configs

pkg/transformerconfig/defaultconfig/defaultconfig.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package defaultconfig provides the default
+// transformer configurations
+package defaultconfig
+
+import (
+	"bytes"
+)
+
+// GetDefaultPathConfigs returns the default pathConfigs data
+func GetDefaultPathConfigs() []byte {
+	configData := [][]byte{
+		[]byte(namePrefixPathConfigs),
+	}
+	return bytes.Join(configData, []byte(`\n`))
+}

pkg/transformerconfig/defaultconfig/namePrefix.go

@@ -0,0 +1,24 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package defaultconfig
+
+const (
+	namePrefixPathConfigs = `
+namePrefix:
+- path: metadata/name
+`
+)

pkg/transformerconfig/pathconfig.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package transformerconfig
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"strings"
+)
+
+// PathConfig contains the configuration of a field, including the gvk it ties to,
+// path to the field, etc.
+type PathConfig struct {
+	Group              string `json:"group,omitempty" yaml:"group,omitempty"`
+	Version            string `json:"version,omitempty" yaml:"version,omitempty"`
+	Kind               string `json:"kind,omitempty" yaml:"kind,omitempty"`
+	Path               string `json:"path,omitempty" yaml:"path,omitempty"`
+	CreateIfNotPresent bool   `json:"create,omitempty" yaml:"create,omitempty"`
+}
+
+// Gvk returns GroupVersionKind of the pathConfig
+func (p PathConfig) Gvk() *schema.GroupVersionKind {
+	return &schema.GroupVersionKind{
+		Group:   p.Group,
+		Version: p.Version,
+		Kind:    p.Kind,
+	}
+}
+
+// PathSlice converts the path string to a slice of strings, separated by "/"
+func (p PathConfig) PathSlice() []string {
+	return strings.Split(p.Path, "/")
+}

pkg/transformerconfig/referencepathconfig.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package transformerconfig
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// ReferencePathConfig contains the configuration of a field that references
+// the name of another resource whose GroupVersionKind is specified in referencedGVK.
+// e.g. pod.spec.template.volumes.configMap.name references the name of a configmap
+// Its corresponding referencePathConfig will look like:
+//
+//	ReferencePathConfig{
+//	referencedGVK: schema.GroupVersionKind{Version: "v1", Kind: "ConfigMap"},
+//	pathConfigs: []PathConfig{
+//		{
+//			GroupVersionKind: &schema.GroupVersionKind{Version: "v1", Kind: "Pod"},
+//			Path:             []string{"spec", "volumes", "configMap", "name"},
+//		},
+//	}
+type ReferencePathConfig struct {
+	Group   string `json:"group,omitempty" yaml:"group,omitempty"`
+	Version string `json:"version,omitempty" yaml:"version,omitempty"`
+	Kind    string `json:"kind,omitempty" yaml:"kind,omitempty"`
+	// PathConfig is the gvk that is referencing the referencedGVK object's name.
+	PathConfigs []PathConfig `json:"pathConfigs,omitempty" yaml:"pathConfigs,omitempty"`
+}
+
+// Gvk returns GroupVersionKind of the reference pathConfig
+func (p ReferencePathConfig) Gvk() *schema.GroupVersionKind {
+	return &schema.GroupVersionKind{
+		Group:   p.Group,
+		Version: p.Version,
+		Kind:    p.Kind,
+	}
+}
+
+func merge(configs []ReferencePathConfig, config ReferencePathConfig) []ReferencePathConfig {
+	var result []ReferencePathConfig
+	found := false
+	for _, c := range configs {
+		if c.Gvk() == config.Gvk() {
+			c.PathConfigs = append(c.PathConfigs, config.PathConfigs...)
+			found = true
+		}
+		result = append(result, c)
+	}
+
+	if !found {
+		result = append(result, config)
+	}
+	return result
+}
+
+func mergeNameReferencePathConfigs(a, b []ReferencePathConfig) []ReferencePathConfig {
+	for _, r := range b {
+		a = merge(a, r)
+	}
+	return a
+}

pkg/transformerconfig/transformerconfig.go

@@ -0,0 +1,73 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package transformerconfig provides the functions to load default or user provided configurations
+// for different transformers
+package transformerconfig
+
+import (
+	"github.com/ghodss/yaml"
+	"sigs.k8s.io/kustomize/pkg/loader"
+)
+
+// TransformerConfig represents the path configurations for different transformations
+type TransformerConfig struct {
+	NamePrefix        []PathConfig          `json:"namePrefix,omitempty" yaml:"namePrefix,omitempty"`
+	NameSpace         []PathConfig          `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+	CommonLabels      []PathConfig          `json:"commonLabels,omitempty" yaml:"commonLabels,omitempty"`
+	CommonAnnotations []PathConfig          `json:"commonAnnotations,omitempty" yaml:"commonAnnotations,omitempty"`
+	NameReference     []ReferencePathConfig `json:"nameReference,omitempty" yaml:"nameReference,omitempty"`
+	VarReference      []PathConfig          `json:"varReference,omitempty" yaml:"varReference,omitempty"`
+}
+
+// Merge merges two TransformerConfigs objects into a new TransformerConfig object
+func (t *TransformerConfig) Merge(input *TransformerConfig) *TransformerConfig {
+	merged := &TransformerConfig{}
+	merged.NamePrefix = append(t.NamePrefix, input.NamePrefix...)
+	merged.NameSpace = append(t.NameSpace, input.NameSpace...)
+	merged.CommonAnnotations = append(t.CommonAnnotations, input.CommonAnnotations...)
+	merged.CommonLabels = append(t.CommonLabels, input.CommonLabels...)
+	merged.VarReference = append(t.VarReference, input.VarReference...)
+	merged.NameReference = mergeNameReferencePathConfigs(t.NameReference, input.NameReference)
+	return merged
+}
+
+// MakeTransformerConfigFromFiles returns a TranformerConfig object from a list of files
+func MakeTransformerConfigFromFiles(ldr loader.Loader, paths []string) (*TransformerConfig, error) {
+	result := &TransformerConfig{}
+	for _, path := range paths {
+		data, err := ldr.Load(path)
+		if err != nil {
+			return nil, err
+		}
+		t, err := MakeTransformerConfigFromBytes(data)
+		if err != nil {
+			return nil, err
+		}
+		result = result.Merge(t)
+	}
+	return result, nil
+}
+
+// MakeTransformerConfigFromBytes returns a TransformerConfig object from bytes
+func MakeTransformerConfigFromBytes(data []byte) (*TransformerConfig, error) {
+	var t TransformerConfig
+	err := yaml.Unmarshal(data, &t)
+	if err != nil {
+		return nil, err
+	}
+	return &t, nil
+}